;(() => {
  // 类的访问类型 private protected public
  class Person {
    protected name: string = '1111'
    public sayHello() {
      return this.name + '你好呀'
    }
  }

  class Teacher extends Person {
    sayHello() {
      return this.name
    }
  }
  const person = new Person()
  // person.name = '哈'
  // console.log(person.name)
  console.log(person.sayHello())
  const teacher = new Teacher()
  console.log(teacher.sayHello())
})()
